I didn't claim it was me who found out, just spreading the word. :)

Woot! I'm off to try this.

I have a 4890 which used to run at 240Mhz, after the latest beta patch it runs at 500Mhz. The maximum factory specified clock speed is 850 Mhz.

I set it to 850Mhz with Ati tray tools and got 30 or so extra FPS, but i don't know what else to change there (fan profiles, voltage, etc) so it ends up crashing and rebooting my PC after 40 minutes or so. I guess the catalyst drivers automatically take care of these things, because it uses 850Mhz on all of my other games without any problems.

If you solution works then the sim is fully playable for me. I'm currently getting 20-30 FPS with the GPU at 500Mhz and 50+ FPS if i run it at 850Mhz. While 30 is very playable for me, it gives less of a margin for them to drop when there's a lot of things suddenly happening at once on the screen. On the other hand, 50 is just great as i'm limited to 60 FPS anyway due to having Vsync on and a 60Hz monitor.

I'm off to try it, wish me luck ;)

Did it work Blackdog? Interested to see if my fix works for all the ATI cards suffering the underclocking issue, the more positives we can get the better!

So, i renamed the video file containing the animation of the Ubi logo and had a go late last night. I didn't have time to do in-depth tests, just a quick go in the low altitude bomber intercept mission.

Long story short, i can't really verify it but it seems to work.

To be more precise, when i alt-tab out of the sim to check what CCC says my clock speeds are, it shows it's underclocked to 240Mhz. However, when in the sim it's noticeably smoother than before.

My suspicion is that getting rid of the logo lets the drivers recognize there's a game running and from that point on, it dynamically throttles the GPU up/down as needed, clocking up when in-game and undeclocking it back down once i alt-tab to the desktop.
I mean, i do get the 240Mhz indication in the CCC when i alt-tab out of CoD, but when actually flying i was getting an average of 24FPS with a maximum of 50 (as displayed by the in-game fps counter). I think it was also a bit misleading as i ran the mission for just one or two passes and that included the initial merge where all the textures load, so the sample range was a bit "biased" to the low side. If i had played through it for 10 minutes or so i guess the average would be around 30-35 FPS as it certainly hovered around 30-40 FPS for the remainder of the mission with maximum in the 50s, compared to 25FPS with a maximum of 30+ before renaming the video file.

This is still lower than what i got by forcing 850Mhz via the Ati tray tools (that gave me an almost constant 40 FPS all the way into the high 50s), but it's still a perfectly working solution.

The biggest improvement was that it completely eliminated the stutters that used to happen as the textures loaded the first time i would approach bombers or go to zoom view.

Until the sim is further optimized, this temporary workaround gets a thumbs up from me. Just remember to go back and rename the video file again after each patch or whenever you verify the integrity of the game files via Steam, because it will revert it to its default state.

Hello, excuse me for my english, I have the same ring than orphéus

core I5 2.7 Ghz W7 64b 4 GB RAM and two ATI 5770 1 GB in CROSS OVER

and it's works very well for me ...

from 15 20fps to 30 40 fps with no stutters

by

I wonder if this can work for Nvidia cards too??

Glad it's been an improvement. What seems to be happening, as I said before is that the Ubi splash forces the card to video clock speeds, but Powerplay (or whatever) isn't detecting the swap back to 3D speeds. If you check GPU-Z and make sure that it's refreshing while not on screen, you should be able to see if your card is clocking full during gameplay. Without the splash movie confusing the card, the game seems to clock normally :)


If Nvidia cards are underclocking in the same way as the ATI ones then I see no reason why not - it's simply a case of the UVD setting overriding the usual 3D setting when the splash plays. To the best of my knowledge though, I've not seen any reports from Nvidia users complaining about underclocking, so afaik this is an ATI only issue.

Nvid cards wont be affected UVD is an ATI program

Do you mean powercolor cards ?

I have a HD4890 1 GB powercolor and I am not to sure if I have an a improvment.

It still stutters down low sooooo not sure.

O_Smiladon

Ahh right, thanks for the info!


Smiladon - no, I mean the ATI Powerplay function:

http://www.amd.com/us/products/techn...ower-play.aspx

All it does is throttle up/down the GPU depending on load. It should detect changes and throttle the card appropriately. The Ubi splash video that plays on startup was locking the card to video speeds (UVD) and the Powerplay function wasn't detecting the return to 3D, so the game was effectively running on half a graphics card.

For ATI cards with the underclocking problem, when running GPU-Z I saw a max clock spike on initial load, then the Ubi splash locks the GPU clock at 400mhz. Removing/renaming the .wmv file solves the problem as there's no transition from 3D to 2D clocks - the game runs at full 3D clock speed.

If you're not sure if you have this issue, run GPU-Z before you load CloD and see how your GPU clocks up. If it's stuck at half clock speeds (400mhz in my case, may differ for different cards), try renaming the ubi splash. Not all ATI cards are affected by this issue, so if your card clocks properly there's no need to do it - but if your card isn't clocking properly, this will solve it & give you a nice performance boost.